About the lab
Our lab research is focused on nanomaterials preparation and characterization. Second topic are semiconductors.
Featured research (14)
The development of sensitive, selective, and reliable gaseous hydrogen peroxide (H2O2) sensors operating at room temperature still represents a remaining challenge. In this work, we have investigated and combined the advantageous properties of a two-dimensional Ti3C2Tx MXene material that exhibits a large specific surface area and high surface activity, with favorable conducting and stabilizing properties of chitosan. The MXene–chitosan membrane was deposited on the ferrocyanide-modified screen-printed working carbon electrode, followed by applying poly(acrylic acid) as an electrolyte and accumulation medium for gaseous H2O2. The sensor showed highly sensitive and selective electroanalytical performance for detecting trace concentrations of gaseous H2O2 with a very low detection limit of 4 μg m–3 (4 ppbv), linear response in the studied concentration range of 0.5–30.0 mg m–3, and good reproducibility with an RSD of 1.3%. The applicability of the sensor was demonstrated by point-of-interest detection of gaseous H2O2 during the real hair bleaching process with a 9 and 12% H2O2 solution.
2D materials are being widely investigated for their potential application in light‐detecting devices. Very recently, a spin‐coated flexible 2D germanium‐based photodetector with great photocurrent density and responsivity as well as short rise and decay time is presented by Liu et. al. In this paper, the solid‐state single flake photodetector base on either pure germanane or (3‐hydroxypropyl)germanane is reported. Both prepared photodetectors while irradiated with different wavelengths of light exhibit outstanding responsivity of 1157 mA W ⁻¹ for GeH and 362 mA W ⁻¹ for (3‐hydroxypropyl)germanane, which exceeds Liu's flexible reported GeH photodetector (22 µA W ⁻¹ ) by more than five orders of magnitude. These constructed photodetectors also exhibit rise and fall times lower than 20 ms, which is also significantly faster than the GeH photodetector reported by Liu with rise and decay times 240 and 740 ms, respectively.
The development of new materials for electromagnetic interference (EMI) shielding is an important area of research, as it allows for the creation of more effective and high-efficient shielding solutions. In this sense, MXenes, a class of 2D transition metal carbides and nitrides have exhibited promising performances as EMI shielding materials. Electric conductivity, low density, and flexibility are some of the properties given by MXene materials, which make them very attractive in the field. Different processing techniques have been employed to produce MXene-based materials with EMI shielding properties. This review summarizes processes and the role of key parameters like the content of fillers and thickness in the desired EMI shielding performance. It also discusses the determination of power coefficients in defining the EMI shielding mechanism and the concept of green shielding materials, as well as their influence on the real application of a produced material. The review concludes with a summary of current challenges and prospects in the production of MXene materials as EMI shields.
Considerable improvements in the electrocatalytic activity of 2D metal phosphorous trichalcogenides (M2P2X6) have been achieved for water electrolysis, mostly with MII2[P2X6]4− as catalysts for hydrogen evolution reaction (HER). Herein, MIMIIIP2S6 (MI = Cu, Ag; MIII = Sc, V, Cr, In) are synthesized and tested for the first time as electrocatalysts in alkaline media, towards oxygen reduction reaction (ORR) and HER. AgScP2S6 follows a 4 e− pathway for the ORR at 0.74 V versus reversible hydrogen electrode; CuScP2S6 is active for HER, exhibiting an overpotential of 407 mV and a Tafel slope of 90 mV dec−1. Density functional theory models reveal that bulk AgScP2S6 and CuScP2S6 are both semiconductors with computed bandgaps of 2.42 and 2.23 eV, respectively and overall similar electronic properties. Besides composition, the largest difference in both materials is in their molecular structure, as Ag atoms sit at the midpoint of each layer alongside Sc atoms, while Cu atoms are raised to a similar height to S atoms, in the external segment of the 2D layers. This structural difference probably plays a fundamental role in the different catalytic performances of these materials. These findings show that MI(Cu, Ag) together with Sc(MIII) leads to promising achievements in MIMIIIP2S6 materials as electrocatalysts.
- Department of Inorganic Chemistry
About Zdenek Sofer
- Zdenek Sofer currently works at the Department of Inorganic Chemistry, University of Chemistry and Technology, Prague. Zdenek does research in Material Chemistry, Solid-state Chemistry and 2D materials. Their current project is focused on 2D materials.